Objective: To determine if quantitative assessment of a reduced number of joints provides information equivalent to that obtained by the traditional 60-joint evaluation in detecting changes in patients participating in clinical trials of rheumatoid arthritis (RA).
Methods: The changes in quantitative joint scores of patients from 3 previously reported clinical trials were compiled and compared with changes in quantitative scores derived using a reduced number of joints. Effect sizes were calculated (mean change in joint score/standard deviation of joint score) and compared for the different joint indices.
Results: The effect sizes of the joint scores derived using a reduced number of joints were similar to those of the original 60-joint score. The reduced joint count scores revealed significant changes for clinical trials involving as few as 15 patients.
Conclusion: Reduced joint count scores may be used to evaluate the results of clinical trials without decreasing the ability to detect change over time. Quantitative assessment of a reduced number of joints may also facilitate assessment of responses to treatment in the routine care of patients with RA.